/*
 * linux/include/linux/sunrpc/gss_api.h
 *
 * Somewhat simplified version of the gss api.
 *
 * Dug Song <dugsong@monkey.org>
 * Andy Adamson <andros@umich.edu>
 * Bruce Fields <bfields@umich.edu>
 * Copyright (c) 2000 The Regents of the University of Michigan
 */

#ifndef _LINUX_SUNRPC_GSS_API_H
#define _LINUX_SUNRPC_GSS_API_H

#ifdef __KERNEL__
#include <linux/sunrpc/xdr.h>
#include <linux/uio.h>

/* The mechanism-independent gss-api context: */
struct gss_ctx {
	struct gss_api_mech *mech_type;
	void *internal_ctx_id;
};

#define GSS_C_NO_BUFFER		((struct xdr_netobj) 0)
#define GSS_C_NO_CONTEXT	((struct gss_ctx *) 0)
#define GSS_C_NULL_OID		((struct xdr_netobj) 0)

/*XXX  arbitrary length - is this set somewhere? */
#define GSS_OID_MAX_LEN 32

/* gss-api prototypes; note that these are somewhat simplified versions of
 * the prototypes specified in RFC 2744. */
int gss_import_sec_context(const void *input_token,
			   size_t bufsize,
			   struct gss_api_mech *mech, struct gss_ctx **ctx_id);
u32 gss_get_mic(struct gss_ctx *ctx_id,
		struct xdr_buf *message, struct xdr_netobj *mic_token);
u32 gss_verify_mic(struct gss_ctx *ctx_id,
		   struct xdr_buf *message, struct xdr_netobj *mic_token);
u32 gss_wrap(struct gss_ctx *ctx_id,
	     int offset, struct xdr_buf *outbuf, struct page **inpages);
u32 gss_unwrap(struct gss_ctx *ctx_id, int offset, struct xdr_buf *inbuf);
u32 gss_delete_sec_context(struct gss_ctx **ctx_id);

u32 gss_svc_to_pseudoflavor(struct gss_api_mech *, u32 service);
u32 gss_pseudoflavor_to_service(struct gss_api_mech *, u32 pseudoflavor);
char *gss_service_to_auth_domain_name(struct gss_api_mech *, u32 service);

struct pf_desc {
	u32 pseudoflavor;
	u32 service;
	char *name;
	char *auth_domain_name;
};

/* Different mechanisms (e.g., krb5 or spkm3) may implement gss-api, and
 * mechanisms may be dynamically registered or unregistered by modules. */

/* Each mechanism is described by the following struct: */
struct gss_api_mech {
	struct list_head gm_list;
	struct module *gm_owner;
	struct xdr_netobj gm_oid;
	char *gm_name;
	const struct gss_api_ops *gm_ops;
	/* pseudoflavors supported by this mechanism: */
	int gm_pf_num;
	struct pf_desc *gm_pfs;
};

/* and must provide the following operations: */
struct gss_api_ops {
	int (*gss_import_sec_context) (const void *input_token,
				       size_t bufsize, struct gss_ctx * ctx_id);
	 u32(*gss_get_mic) (struct gss_ctx * ctx_id,
			    struct xdr_buf * message,
			    struct xdr_netobj * mic_token);
	 u32(*gss_verify_mic) (struct gss_ctx * ctx_id,
			       struct xdr_buf * message,
			       struct xdr_netobj * mic_token);
	 u32(*gss_wrap) (struct gss_ctx * ctx_id,
			 int offset,
			 struct xdr_buf * outbuf, struct page ** inpages);
	 u32(*gss_unwrap) (struct gss_ctx * ctx_id,
			   int offset, struct xdr_buf * buf);
	void (*gss_delete_sec_context) (void *internal_ctx_id);
};

int gss_mech_register(struct gss_api_mech *);
void gss_mech_unregister(struct gss_api_mech *);

/* returns a mechanism descriptor given an OID, and increments the mechanism's
 * reference count. */
struct gss_api_mech *gss_mech_get_by_OID(struct xdr_netobj *);

/* Returns a reference to a mechanism, given a name like "krb5" etc. */
struct gss_api_mech *gss_mech_get_by_name(const char *);

/* Similar, but get by pseudoflavor. */
struct gss_api_mech *gss_mech_get_by_pseudoflavor(u32);

/* Just increments the mechanism's reference count and returns its input: */
struct gss_api_mech *gss_mech_get(struct gss_api_mech *);

/* For every successful gss_mech_get or gss_mech_get_by_* call there must be a
 * corresponding call to gss_mech_put. */
void gss_mech_put(struct gss_api_mech *);

#endif /* __KERNEL__ */
#endif /* _LINUX_SUNRPC_GSS_API_H */
